kernel/linux.git/fs/hostfs, branch v6.6.132

um: hostfs: avoid issues on inode number reuse by host

2025-04-10T12:37:34+00:00

[ Upstream commit 0bc754d1e31f40f4a343b692096d9e092ccc0370 ] Some file systems (e.g. ext4) may reuse inode numbers once the inode is not in use anymore. Usually hostfs will keep an FD open for each inode, but this is not always the case. In the case of sockets, this cannot even be done properly. As such, the following sequence of events was possible: * application creates and deletes a socket * hostfs creates/deletes the socket on the host * inode is still in the hostfs cache * hostfs creates a new file * ext4 on the outside reuses the inode number * hostfs finds the socket inode for the newly created file * application receives -ENXIO when opening the file As mentioned, this can only happen if the deleted file is a special file that is never opened on the host (i.e. no .open fop). As such, to prevent issues, it is sufficient to check that the inode has the expected type. That said, also add a check for the inode birth time, just to be on the safe side. Fixes: 74ce793bcbde ("hostfs: Fix ephemeral inodes") Signed-off-by: Benjamin Berg Reviewed-by: Mickaël Salaün Tested-by: Mickaël Salaün Link: https://patch.msgid.link/20250214092822.1241575-1-benjamin@sipsolutions.net Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin

Revert "hostfs: convert hostfs to use the new mount API"

2025-02-11T08:37:33+00:00

This reverts commit d073828fe0f5cd9531bb918ab0b5a7b920b1bfdb which is commit cd140ce9f611a5e9d2a5989a282b75e55c71dab3 upstream. It is reported to cause build issues and odds are the root problem isn't really an issue on the 6.6.y branch anyway. If it is, someone can provide a working set of backported patches. Reported-by: Guenter Roeck Link: https://lore.kernel.org/r/cd10a924-ae65-4b02-aea2-e629947ca7a3@roeck-us.net Cc: Hongbo Li Cc: Christian Brauner Cc: Sasha Levin Signed-off-by: Greg Kroah-Hartman

Revert "hostfs: fix string handling in __dentry_name()"

2025-02-11T08:37:33+00:00

This reverts commit 86ec56b25476758f708328b2eeed68918567efd0 which is commit 60a6002432448bb3f291d80768ae98d62efc9c77 upstream. It is reported to cause build issues and odds are the root problem isn't really an issue on the 6.6.y branch anyway. If it is, someone can provide a working set of backported patches. Reported-by: Guenter Roeck Link: https://lore.kernel.org/r/cd10a924-ae65-4b02-aea2-e629947ca7a3@roeck-us.net Cc: Hongbo Li Cc: Christian Brauner Cc: Sasha Levin Cc: Al Viro Signed-off-by: Greg Kroah-Hartman

Revert "hostfs: Add const qualifier to host_root in hostfs_fill_super()"

2025-02-11T08:37:33+00:00

This reverts commit 1fbe93dd7e6a0dab59a5fce99f16703f7d52ed81 which is commit 104eef133fd9c17e4dc28bf43f592a86f26d8a59 upstream. It is reported to cause build issues and odds are the root problem isn't really an issue on the 6.6.y branch anyway. If it is, someone can provide a working set of backported patches. Reported-by: Guenter Roeck Link: https://lore.kernel.org/r/cd10a924-ae65-4b02-aea2-e629947ca7a3@roeck-us.net Cc: Hongbo Li Cc: Christian Brauner Cc: Sasha Levin Cc: Nathan Chancellor Cc: Richard Weinberger Signed-off-by: Greg Kroah-Hartman

Revert "hostfs: fix the host directory parse when mounting."

2025-02-11T08:37:32+00:00

This reverts commit be80de30b347dc2eae35dd5f7905ad9c9167dc08 which is commit ef9ca17ca458ac7253ae71b552e601e49311fc48 upstream. It is reported to cause build issues and odds are the root problem isn't really an issue on the 6.6.y branch anyway. If it is, someone can provide a working set of backported patches. Reported-by: Guenter Roeck Link: https://lore.kernel.org/r/cd10a924-ae65-4b02-aea2-e629947ca7a3@roeck-us.net Cc: Hongbo Li Cc: Christian Brauner Cc: Sasha Levin Signed-off-by: Greg Kroah-Hartman

hostfs: fix the host directory parse when mounting.

2025-02-08T08:52:33+00:00

commit ef9ca17ca458ac7253ae71b552e601e49311fc48 upstream. hostfs not keep the host directory when mounting. When the host directory is none (default), fc->source is used as the host root directory, and this is wrong. Here we use `parse_monolithic` to handle the old mount path for parsing the root directory. For new mount path, The `parse_param` is used for the host directory parse. Reported-and-tested-by: Maciej Żenczykowski Fixes: cd140ce9f611 ("hostfs: convert hostfs to use the new mount API") Link: https://lore.kernel.org/all/CANP3RGceNzwdb7w=vPf5=7BCid5HVQDmz1K5kC9JG42+HVAh_g@mail.gmail.com/ Cc: Christian Brauner Signed-off-by: Hongbo Li Link: https://lore.kernel.org/r/20240725065130.1821964-1-lihongbo22@huawei.com [brauner: minor fixes] Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman

hostfs: Add const qualifier to host_root in hostfs_fill_super()

2025-02-08T08:52:32+00:00

commit 104eef133fd9c17e4dc28bf43f592a86f26d8a59 upstream. After the recent conversion to the new mount API, there is a warning when building hostfs (which may be upgraded to an error via CONFIG_WERROR=y): fs/hostfs/hostfs_kern.c: In function 'hostfs_fill_super': fs/hostfs/hostfs_kern.c:942:27: warning: initialization discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers] 942 | char *host_root = fc->source; | ^~ Add the 'const' qualifier, as host_root will not be modified after its assignment. Move the assignment to keep the existing reverse Christmas tree order intact. Fixes: cd140ce9f611 ("hostfs: convert hostfs to use the new mount API") Signed-off-by: Nathan Chancellor Link: https://lore.kernel.org/r/20240611-hostfs-fix-mount-api-conversion-v1-1-ef75bbc77f44@kernel.org Acked-by: Richard Weinberger Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman

hostfs: fix string handling in __dentry_name()

2025-02-08T08:52:32+00:00

[ Upstream commit 60a6002432448bb3f291d80768ae98d62efc9c77 ] strcpy() should not be used with destination potentially overlapping the source; what's more, strscpy() in there is pointless - we already know the amount we want to copy; might as well use memcpy(). Fixes: c278e81b8a02 "hostfs: Remove open coded strcpy()" Signed-off-by: Al Viro Signed-off-by: Sasha Levin

hostfs: convert hostfs to use the new mount API

2025-02-08T08:52:32+00:00

[ Upstream commit cd140ce9f611a5e9d2a5989a282b75e55c71dab3 ] Convert the hostfs filesystem to the new internal mount API as the old one will be obsoleted and removed. This allows greater flexibility in communication of mount parameters between userspace, the VFS and the filesystem. See Documentation/filesystems/mount_api.txt for more information. Signed-off-by: Hongbo Li Link: https://lore.kernel.org/r/20240530120111.3794664-1-lihongbo22@huawei.com Signed-off-by: Christian Brauner Stable-dep-of: 60a600243244 ("hostfs: fix string handling in __dentry_name()") Signed-off-by: Sasha Levin

hostfs: fix dev_t handling

2024-08-03T06:54:22+00:00

commit 267ed02c2121b75e0eaaa338240453b576039e4a upstream. dev_t is a kernel type and may have different definitions in kernel and userspace. On 32-bit x86 this currently makes the stat structure being 4 bytes longer in the user code, causing stack corruption. However, this is (potentially) not the only problem, since dev_t is a different type on user/kernel side, so we don't know that the major/minor encoding isn't also different. Decode/encode it instead to address both problems. Cc: stable@vger.kernel.org Fixes: 74ce793bcbde ("hostfs: Fix ephemeral inodes") Link: https://patch.msgid.link/20240702092440.acc960585dd5.Id0767e12f562a69c6cd3c3262dc3d765db350cf6@changeid Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman